环境温湿度对粘土干缩裂缝结构形态影响  

Influence of environment temperature and humidity on structural morphology of desiccation fissures in clay

作　　者：周东[1,2] 王利明[1,2] 欧孝夺[1,2] 王业田[1,2] 

机构地区：[1]广西大学土木建筑工程学院,广西南宁530004 [2]广西大学工程防灾与结构安全教育部重点实验室,广西南宁530004

出　　处：《广西大学学报（自然科学版）》2012年第2期204-209,共6页Journal of Guangxi University（Natural Science Edition）

基　　金：国家自然科学基金资助项目(40772190);广西理工科学实验中心重点项目(LGZX201103);广西区教育厅科研基金项目(T081007)

摘　　要：为研究环境温度、湿度作用下粘土干缩裂缝的结构形态与变化规律,以南宁市河流冲积相粘土为研究对象,将制成饱和泥浆的土样分别放置在40、50、60、70℃四种温度和相对湿度为50%、70%、90%三种湿度环境下,使其失水、干缩开裂至稳定,观察分析土样干缩裂缝的结构特征和变化规律。试验结果表明:随温度升高,土样失水稳定时裂缝率、分维数、块区个数呈增大趋势,平均块区面积、最大块区面积则呈减小趋势;随着湿度增加,裂缝率、分维数、平均块区面积减小,块区个数和最大块区面积增加;裂缝率和分维数与含水量均具有良好的线性关系,二者随含水量的变化速率受环境温湿度影响;块区面积分布函数的峰值随温湿度升高而增大,块区最可几面积则逐渐减小。In order to study the structural morphology and development of desiccation fissure in clay influenced by environment temperature and humidity,the river alluvial clay in Nanning was investigated,and its slurry soil samples were exposed to temperatures of 40 ℃,50 ℃,60 ℃ and 70 ℃ and relative humidity of 50%,70% and 90%,respectively.The samples were hydrated,and an observation on the structural morphology of the desiccation fissures of the samples was carried out after shrinkage cracking of the samples became stable.The results show that as the temperature rises,the cracking rate,fractal dimension and number of blocks tend to increase,and area of the average and largest block tend to decrease;as humidity increases,the cracking rate,fractal dimension and area of the average block tend to decrease,and the number of blocks and the area of the largest block tend to increase;both cracking rate and fractal dimension have a good linear relationship with water content,and their changing rates related with water content are influenced by environment temperature and humidity;peak of the distribution function of block area increases as the environment temperature and humidity rise,while the most probable block area decreases gradually.

关 键 词：温度 湿度 干缩裂缝 几何特征 非饱和土 

分 类 号：P642.11[天文地球—工程地质学]